In other words, for £25 (currently), they're absolutely fantastic. The frequency range is slightly larger than the average earphone and I believe a low-end was boosted sightly so you get a more 'natural feel' in your ears. These are a ridiculously massive improvement on the previous earphones and in comparison to other earphones at that price, you get a lot of sound for your money!

The impedance of the Apple earpods is actually ~45 Ohm. Samuel G is wrong, he is likely referring to the older earBUDS. The question here is for the newer earPODS! Multiple sources from Head-Fi suggest between 42 Ohm and 45 Ohm. Actual lab results prove this to be correct. No official documentation from Apple can be found.

Here is just one of the high end test results from an audiophile professional (also aligns with ~45 Ohm impedance):